This invention relates to a flexible elongate device having a distal extremity of adjustable stiffness and method which is particularly adapted for use as a catheter or a guide wire.
In certain medical procedures, as for example in angioplasty procedures, a catheter having an integral guide wire tip or a guide wire which is able to be deployed through the coronary arteries has been used until a stenosis is reached in the coronary artery that fully or substantially occludes the artery. In the past, it has been difficult if not impossible to negotiate such stenoses in the artery because the tip of the guide wire or catheter is very floppy and typically will buckle under the resistance provided by the stenosis. There is therefore a need for a device which will overcome this difficulty.
In general, it is the object of the present invention to provide a flexible elongate device having a distal extremity of adjustable stiffness and a method to make it possible to penetrate occlusions in vessels of a patient.
Another object of the invention is to provide a device and method of the above character in which the stiffness of the distal extremity can be adjusted during the time that the distal extremity is disposed in the coronary vessel.
Another object of the invention is to provide a device and method of the above character in which the distal extremity is steerable.
Another object of the invention is to provide a device and method of the above character in which a hand-held control mechanism is utilized to adjust the stiffness.
Another object of the invention is to provide a device and method of the above character which can be used in conjunction with the balloon dilatation catheter.
Additional objects and features of the invention will appear from the following description in which the preferred embodiments are set forth in detail in conjunction with the accompanying drawings.